Within the next week, any abandoned games (inactive for 6 months) will be declared a draw. If both players are inactive, the unfinished games will simply be deleted.
This process will happen periodically in the future.
edit : An amendment to the above, all unfinished games may be deleted, regardless of player activity, if they are not part of a clan challenge, tournament, etc. I will clarify this nearer the time. But house keeping of some form for abandoned games will take place.
edit : 2009-01-28 - They will be deleted, and not declared a draw.